CarCostCheck

MERCEDES G-CLASS (2018)

Running costs, common problems, and reliability data based on 807 real MOT tests in 2024.

Share:XFacebookWhatsApp

MOT Pass Rate

94%

Total Tests (2024)

807

Avg Mileage

39,199 mi

Est. Annual Cost

£1,690

Is the 2018 MERCEDES G-CLASS reliable?

Excellent reliability. Very few MOT failures. That's 12 points above the national average of 82%. It also outperforms the MERCEDES brand average of 87%.

At 6 years old, 94% of MERCEDES G-CLASSs from 2018 passed their MOT first time in 2024. That's based on 807 tests across the UK. The average mileage at this age is 39,199 miles.

How does the 2018 MERCEDES G-CLASS compare?

Rank among all 2018 cars135th out of 649(top 21%)
Rank among all MERCEDES models301th out of 1,408(top 21%)
vs national average+12% (82% avg)
vs 2018 cars average+5% (89% avg)
vs MERCEDES average+7% (87% avg)

Mileage Analysis

The average 2018 MERCEDES G-CLASS has 39,199 miles on the clock, which is in line with the expected 44,400 miles for a 6-year-old car, suggesting normal everyday use.

Best year to buy a MERCEDES G-CLASS?

The most reliable year is the 2020 model with a 98% MOT pass rate, while the 2021 model has the lowest at 78%. The 2018 sits between the two at 94%.

How much does a 2018 MERCEDES G-CLASS cost to run?

⛽Fuel (Diesel, 2987cc)
£1,245
🏛️Road Tax
£190
🔧MOT Test
£55
🛠️Predicted Repairs
£200
Total per year£1,690
Per month£141/mo

Based on 7,400 miles/year (UK average), current fuel prices, and repair likelihood from MOT pass rate data. Insurance not included.

MERCEDES G-CLASS by Year

YearPass RateTestsAvg Mileage
202178%6530,190 mi
202098%6632,570 mi
201996%31941,698 mi
201894%80739,199 mi
201786%69143,730 mi
201694%60458,012 mi
201588%59148,991 mi
201492%36254,969 mi
201394%44969,675 mi
201290%22176,209 mi
201196%9270,666 mi
201073%3378,145 mi
2007100%35103,461 mi
200160%4293,234 mi
199982%44113,541 mi

Checking a specific MERCEDES G-CLASS?

Enter the reg plate to see its individual MOT history, mileage verification, and predicted costs.

GB

Free instant check using official DVSA and DVLA data

About the 2018 MERCEDES G-CLASS

The 2018 MERCEDES G-CLASS is a large car with a 2987cc diesel engine. 807 of these vehicles were MOT tested in 2024, making it a less common model in the UK market. It ranks in the top 21% of all 2018 cars for reliability.

With an average of 39,199 miles at 6 years old, MERCEDES G-CLASS owners drive about as much as the UK average.

2018 MERCEDES G-CLASS Fuel Costs

The 2987cc diesel engine is on the larger side, so fuel won't be this car's strong point. Expect around 40 mpg in mixed driving, which works out to roughly £1,245 per year at current diesel prices of 148p per litre (based on 7,400 miles per year). Diesel cars of this age should have their DPF (diesel particulate filter) checked, as replacements can be costly.

What does it cost to own a 2018 MERCEDES G-CLASS?

Total estimated annual running cost is £1,690 (£141/month), broken down as £1245 fuel, £190 road tax, £55 MOT, and £200 predicted repairs. The low repair estimate reflects the excellent 94% pass rate. These cars rarely fail their MOT, so unexpected bills are less likely.

MERCEDES G-CLASS Reliability Trend

The MERCEDES G-CLASS has maintained consistent MOT pass rates across model years, varying by only 1 percentage points.

Buying a Used 2018 MERCEDES G-CLASS

At 6 years old, the MERCEDES G-CLASS offers good value with plenty of life remaining. Most manufacturer warranties will have expired, so a pre-purchase inspection is worth the cost. If you're flexible on year, the 2020 model has the highest pass rate at 98%.

Alternatives to the 2018 MERCEDES G-CLASS

The MERCEDES G-CLASS is actually the most reliable option among similar diesel large cars from this era. Here are comparable diesel cars with similar engines: